In preparation of metallurgical products, which are molten in open or partly closed furnaces, it is necessary to be able to
(1) distribute the raw material correctly in accordance with the furnace process, PA1 (2) crush the contact bridges between the separate electrodes, and PA1 (3) pierce the gas-filled cavities formed and to fill them again. PA1 (a) a circular track disposed adjacent the upper periphery or perimeter of said furnace, PA1 (c) motor means for moving said first transport carriage from one position to another in said circular track, PA1 (d) an elongated non-circular trackway supported by said first transport carriage, said non-circular trackway extending in a generally radial direction with respect to said circular track, PA1 (e) a second transport carriage supported by said elongated non-circular trackway, PA1 (f) means to move said second transport carriage back and forth within said elongated non-circular trackway, PA1 (g) a furnace contents working device connected to said second transport carriage, and PA1 (h) means to vary the angular disposition of said furnace contents working device.
These operations must be carried out to make possible a continuous melting process and in addition, this process must be as economical as possible.
In the working processes so far known these operations are performed with the aid of mobile or partly mobile means, which in addition to the charging of raw materials, also have distributing and stirring functions. Such means are operated by an operator travelling on the machine who is thus exposed to the very unfavorable aspects of the furnace environment.
The high temperature and the gases from the furnace prevent the operator from doing his work effectively, and moreover, they have a direct detrimental effect on him. The machines can also be damaged if they are exposed to a high temperature for a long time, and therefore working cannot, as a rule, take place continuously. Furthermore, stirring machines are known which are mounted at several places around the furnace and by means of which a definite section of the furnace surface can be worked under the control of an operator.
In addition to the unfavorable working conditions these stirring machines have the disadvantage that a large portion of the charging platform cannot be used for other necessary operations. With the development of big furnace units this work has become more and more dangerous and intolerable for man and machine. At these furnaces charging of the raw material is substantially carried out through pipes in the furnace cover.
It is extremely difficult to handle the mobile machines under unfavorable conditions. The least negligence by the attendant may damage the very expensive furnace equipment and the machine.
The problems are especially difficult when furnaces containing electrodes are concerned. The latter must not be damaged when the charge in the vicinity thereof is worked. The electrodes will thus complicate the access to certain parts of the charge surface. Moreover, there is a risk of a flash-over between the furnace and the machine. The present invention is especially suitable for solving these problems, and therefore it is preferred that the present invention be utilized in electric arc furnaces and reduction furnaces of the aforesaid kind.
These difficulties with prior art devices are avoided by the present invention and an effective working of the charge surface is made possible without the operating staff and the material being exposed to the detrimental effects of the furnace environment.